This invention relates to a mixing valve for supplying fluid to a fluid outlet.
Mixing valves can be used to supply tempered, e.g., tepid, water to a water outlet. In some embodiments, cold water from a supply source flows to a cold water inlet, and hot water from a supply source flows to a hot water inlet of the mixing valve. The cold and hot water are mixed in the valve, and mixed, tempered water is directed through a tempered water outlet.
The mixing valves can be used in commercial and/or industrial applications such as, for example, in emergency drench showers and eyewash stations. The tempered water allows a user to rinse relatively comfortably for an adequate amount of time.
This invention relates to a mixing valve.
In one aspect, the invention features a mixing valve including a manifold, a temperature-responsive device, a first by-pass mechanism, and a second by-pass mechanism. The manifold defines a cold fluid inlet, a hot fluid inlet, a fluid outlet in fluid communication with the cold fluid inlet and the hot fluid inlet, and a mixing chamber in fluid communication with the cold fluid inlet, the hot fluid inlet, and the fluid outlet. The temperature-responsive device is capable of regulating the volume of flow from the hot and cold fluid inlets to the mixing chamber. The first by-pass mechanism is responsive to pressure of cold fluid flow in the manifold to allow cold fluid to flow between the cold fluid inlet and the fluid outlet. The second by-pass mechanism is associated with the temperature-responsive device and is responsive to fluid temperature in the manifold to allow cold fluid to flow between the cold fluid inlet and the fluid outlet.
Embodiments may include one or more of the following features. The temperature-responsive device is associated with a first sealing surface and a second sealing surface, the manifold further defines a first seat configured to engage with the first sealing surface, and a second seat configured to engage with the second sealing surface, and the temperature-responsive device is responsive to changes in fluid temperature to control positioning of the first and second surfaces relative to the first and second seats, respectively. The temperature-responsive device is configured to regulate the relative volumes of flow from the cold and hot fluid inlets to the mixing chamber in response to a predetermined temperature setting.
The first by-pass mechanism can be responsive to a pressure differential between cold fluid flow and a constant force, e.g., applied by a spring. The first by-pass mechanism may include a first body and a second body associated with the first body, the second body being responsive to a pressure differential and movable relative to the first body to allow flow of cold fluid through the first body. The first body may slidably receive the second body. The second by-pass mechanism may be associated with the first by-pass mechanism, and may be capable of increasing cold fluid flow allowed by the first by-pass mechanism. The first and second by-pass mechanisms may be mechanically coupled.
In another aspect, the invention features a mixing valve including a manifold defining a cold fluid inlet, a hot fluid inlet, a fluid outlet in fluid communication with the cold fluid inlet and the hot fluid inlet, a mixing chamber in fluid communication with the cold fluid inlet, the hot fluid inlet, and the fluid outlet, a first seat, and a second seat; a temperature-responsive device associated with a first sealing surface configured to engage with the first seat, and a second sealing surface configured to engage with the second seat, the temperature-responsive device being responsive to changes in temperature to adjust positioning of the first and second surfaces relative to the first and second seats, respectively, the positions of the first and second surfaces regulating the flow of cold and hot fluids to the mixing chamber; a first by-pass mechanism responsive to the pressure of cold fluid from the cold fluid inlet to allow cold fluid to flow between the cold fluid inlet and the fluid outlet; and a second by-pass mechanism responsive to a temperature detected by the temperature-responsive device to allow cold fluid flow between the cold fluid inlet and the fluid outlet.
In another aspect, the invention features a method of supplying temperature-regulated fluid. The method includes flowing cold fluid from a cold fluid inlet of a manifold to a fluid outlet of the manifold in response to a pressure of cold fluid from the cold fluid inlet, and flowing cold fluid from the cold fluid inlet to the fluid outlet in response to a temperature of fluid flowing to the fluid outlet.
Embodiments may include one or more of the following features. The method further includes regulating flow of cold fluid from the cold fluid inlet to the fluid outlet, and regulating flow of hot fluid from a hot fluid inlet to the fluid outlet. The method further includes flowing cold fluid in response to the pressure and flowing cold fluid in response to the temperature when flow of hot fluid to the fluid outlet is restricted. The method further includes flowing cold fluid in response to the pressure and flowing cold fluid in response to the temperature when a temperature-responsive device in the manifold malfunctions. The method further includes contracting a portion of the temperature-responsive device. The method further includes restricting flow of hot fluid from a hot fluid inlet of the manifold to the fluid outlet.
In another aspect, the invention features a method of supplying cold fluid to a fluid outlet of a valve manifold when its hot flow path is restricted or when a temperature-responsive device malfunctions, the manifold defining a first cold fluid flow path from a cold fluid inlet of the manifold to the fluid outlet of the manifold, and the hot fluid flow path from a hot fluid inlet of the manifold to the outlet. The method includes flowing cold fluid from the cold fluid inlet to the fluid outlet through a second path different than the first cold fluid flow path in response to a pressure differential, and flowing cold fluid from the cold fluid inlet to the fluid outlet through a third path different than the first and second paths in response to a temperature of fluid flowing to the fluid outlet.
Embodiments may include one or more of the following features. The method includes regulating cold fluid flow through the first flow path, and hot fluid flow through the hot fluid flow path with a temperature-controlling device. The method further includes restricting the flow of hot fluid through the hot fluid flow path when the flow of cold fluid through the first path is restricted. The method further includes restricting flow of hot fluid through the hot fluid flow path when the temperature-responsive device in the manifold malfunctions. The method further includes restricting flow of cold fluid through the first flow path when the temperature-responsive device in the manifold malfunctions. The method further includes contracting a portion of the temperature-responsive device when the temperature-responsive device malfunctions.
The invention provides a mixing valve, for example, for use with an emergency drench shower, an eye/face wash station, or a combination shower and eye/face wash station. Under normal operation, the mixing valve can provide tempered water of a predetermined maximum temperature. The risk of scalding or bums from hot water is thus reduced. Under certain circumstances, such as a hot water failure or a controlling device failure, the mixing valve is capable of safely providing cold water using a by-pass mechanism, such as a dual by-pass mechanism activated by pressure and temperature. The invention further provides a mixing valve having a one-piece design for convenient installation. The mixing valve offers good performance while complying with certain safety requirements, such as OSHA""s ANSI Z358.1-1998.
Other features and advantages of the invention will be apparent from the description of the preferred embodiments thereof and from the claims.